shim: adaptive marker polling, opt-in GPU-side input wait/completion and RGBA8 output

- [Interop] MarkerPollUs = auto is the new default: the input-marker wait learns when
  each feature's inputs become ready, sleeps in <=200 us chunks, yields near the
  prediction and backs off when late (d4r_input_wait.h); a number keeps fixed pacing
  (0 yields). d4r_config.py no longer exports 200 when the key is unset

- D4R_SHIM_GPU_INPUT_WAIT=1 (experimental, split VRAM, age 0): NGX's null stream
  waits on a coherent Vulkan word imported into HIP (d4rStreamWaitValue32Eq) instead
  of CPU polling. The original readback marker stays the authority; a CPU watchdog
  releases discarded lists and timeouts. Denoiser, verify, capture and dilation
  frames keep the CPU wait

- D4R_SHIM_GPU_COMPLETION=1 (needs GPU_INPUT_WAIT): the bridge writes a completion
  word right after the native output kernel (d4rNgxWriteValue32), and the game's queue
  polls it with a bounded compute wait (kernels/support/vulkan_wait.comp), replacing
  the split list's CPU timeline signal. frame_retired writes the same word on every
  failure path

- D4R_SHIM_NATIVE_COMPLETION=1: a null-stream callback in the bridge signals the
  split timeline (d4rNgxTimeline*); D4rFrameCompletion::can_signal only releases the
  oldest outstanding frame

- RGBA8 output: tex_common.h adds an 'R4' redirect tag, so K's native output kernel
  stores packed RGBA8 directly (D4R_SHIM_OUTPUT_RGBA8=1, checked against the kernel
  manifest by d4rOutputKernelRgba8). Host packing handles RGBA8 too.
  patches/vkd3d-proton/0004 (VKD3D_D4R_LINEAR_RGBA8=WxH) makes such outputs linear and
  exportable so the result can be written in place

- D4R_SHIM_FUSE_RGBA8_INPUT=1: one Vulkan pass converts and copies RGBA8 color input
  (vulkan_read.comp mode 5 matches the blit's toward-zero halves, plus a row stride)

- profiling: thread CPU time from the Unix bridge (Wine's GetThreadTimes ticks at
  10 ms); game-queue D3D12 timestamps (vk_input/vk_dlss_wait/vk_output/vk_total);
  gpu_eval split into input_gpu_wait and dlss_gpu; D4R_PROFILE_GPU_EVENTS,
  _TIMESTAMPS, _LOG and _CPU_TIME=0 switch off individual parts for bisection

- bridge: D4R_NGX_STREAM_PRIORITY=high|normal runs NGX on a priority stream
  (off by default; no gain measured)

- release_feature: a feature already marked retiring by a failed drain can still
  be released normally

- harness: RGBA8 with motion and jitter scenes (re-quantized each frame),
  D4R_HARNESS_RGBA8_RAMP, D4R_HARNESS_THRASH_MB to evict L2/Infinity Cache before
  each evaluation

- kernels/native: in_hoist.py and split_output_paths.py (opt-in scheduling
  experiments); scripts/build_k_ldr_output.sh builds K's LDR output with an
  optional D4R_LDR_OUTPUT_MAX_VGPR cap

- tests: test_input_wait.py and test_latency_optimizations.py; MarkerPollUs and
  frame-completion tests updated

patches/vkd3d-proton/0004-linear-rgba8-output.patch

@@ -0,0 +1,35 @@
+vkd3d-proton (d4r, opt-in): VKD3D_D4R_LINEAR_RGBA8=WxH also creates RGBA8 UNORM textures of exactly that size with
+unordered access linear and exportable (with VKD3D_D4R_LINEAR_TEXTURES=1), so the d4r shim can write DLSS's packed
+RGBA8 output in place (D4R_SHIM_INPLACE=1) instead of copying it. Every selected texture is logged (warn).
+Applies on top of 0001-0003.
+
+diff --git a/libs/vkd3d/resource.c b/libs/vkd3d/resource.c
+--- a/libs/vkd3d/resource.c
++++ b/libs/vkd3d/resource.c
+@@ -720,7 +720,25 @@
+             desc->DepthOrArraySize != 1 || desc->SampleDesc.Count != 1 ||
+             (desc->Flags & D3D12_RESOURCE_FLAG_ALLOW_DEPTH_STENCIL))
+         return false;
+-    return format->vk_format == VK_FORMAT_R16G16B16A16_SFLOAT || format->vk_format == VK_FORMAT_A2B10G10R10_UNORM_PACK32;
++    if (format->vk_format == VK_FORMAT_R16G16B16A16_SFLOAT || format->vk_format == VK_FORMAT_A2B10G10R10_UNORM_PACK32)
++        return true;
++    /* VKD3D_D4R_LINEAR_RGBA8=WxH (opt-in, with VKD3D_D4R_LINEAR_TEXTURES=1): also RGBA8 UNORM textures of exactly
++     * that size with unordered access, the shape of a DLSS output, so the shim can write DLSS's packed RGBA8 result
++     * in place. Other RGBA8 targets keep optimal tiling. Every selected texture is logged. */
++    if (format->vk_format == VK_FORMAT_R8G8B8A8_UNORM && (desc->Flags & D3D12_RESOURCE_FLAG_ALLOW_UNORDERED_ACCESS))
++    {
++        static unsigned int selected;
++        unsigned int width = 0, height = 0;
++        char size[32];
++        if (vkd3d_get_env_var("VKD3D_D4R_LINEAR_RGBA8", size, sizeof(size)) &&
++                sscanf(size, "%ux%u", &width, &height) == 2 && desc->Width == width && desc->Height == height)
++        {
++            WARN("d4r: linear exportable RGBA8 texture #%u (%ux%u, flags %#x).\n", ++selected, width, height,
++                    desc->Flags);
++            return true;
++        }
++    }
++    return false;
+ }
+ 
+ static HRESULT vkd3d_get_image_create_info(struct d3d12_device *device,